Swivel chair adjusting means



March 15, 1955 w. H. MOKINLEY SWIVEL CHAIR ADJUSTING MEANS Filed May 17, 1954 INVENTOR W 'L liarro H. McKp'I-c leg ATTORNEY United States Patent SWIVEL CHAIR ADJUSTING MEANS William H. McKinley, Youngstown, Ohio, assignor to The General Fireproofing Company, Youngstown, Ohio, a corporation of Ohio Application May 17, 1954, Serial No. 430,103

4 Claims. (Cl. 155-93) This invention relates to chairs, more particularly to chairs of the swivel type which require adjustment to have the seat at an appropriate height above the floor to suit the users requirements.

One of the objects of the invention is to provide a relatively simple and practical construction which lends itself to appropriate manufacturing procedures, and in its completed form enables the user of a chair to readily and easily adjust the height of the seat without difficulty, and without some of the otherwise laborious and hand soiling manipulations attendant to mechanisms now generally in use.

Another object of the invention is to provide a construction which" utilizes a minimum number of parts and which is reliable in use in the respect that very simple procedures are required to control the height of the adjusting screw relative to the chair base. In that connection the adjusting screw or spindle operates in conjunction with a nut arranged at a fixed level above the chair base, and the spindle may be selectively connected with the chair iron housing for height adjustment or for free swiveling movement when desired, and also permanently connected with the housing so as to avoid axial displacement, as when the chair is lifted by the seat or back.

With the above and other objects in view which will more readily appear as the nature of the invention is better understood, the same consists in the combination and arrangement of parts hereinafter more fully illustrated and claimed.

A preferred and practical embodiment of the invention is shown in the accompanying drawings, in which:

Fig. 1 is a vertical sectional view of the parts with the adjusting screw or spindle at its maximum limit of upward travel relative to the base.

Fig. 2 is a similar vertical sectional view with the spindle at its downward limit of movement.

Similar reference characters designate corresponding parts throughout the several views.

Referring to the drawings, it will be observed that the general assembly includes a chair base designated generally as A and a chair iron B, whose upper portion carries the mechanism for supporting the chair seat, not shown here, because it forms no part of the present invention.

The chair base A includes a center hub casting 1 having a central'bore 2 whose upper portion communicates with a cavity 3 of larger diameter than the bore 2- for accommodating the lower end of a tubular housing 4 depending from the upper portion of the iron B as shown, for'example, in Fig. 2.

The housing 4'is provided at its upper end with an interior socket 5 for receiving the upper end of the adjusting spindle or post 6. As will be seen from the drawing, the bottom of the socket may be provided with a disc D of any suitable lubricous material, such, for example, as nylon. The wall portions of the socket 5 are provided with a radially threaded bore 7 which receives a set screw 8 having a slotted head and a key portion 9 at its inner end for entering an angular groove 10 in the post. The set screw 8 has its key 9 positioned so as to always permit relative free swiveling between the housing 4 and the post 6, and at the same time prevent relative axial displacement of the housing 4 and post 6.

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The wall of the socket 5 is also provided with a manually manipulated clutching or coupling member 11, which, in the example shown, is in the form of an angular body including a handle 12 and a threaded portion 13 for entering the threaded bore 14 of the housing whereby its inner end 15 may be moved into binding engagement with the bottom of the groove 10 of the screw post 6 in order to couple the post and the housing, whereby, rotational movement of the seat carried by the iron B will cause the post to turn in a nut 16 fixed in the upper end of a base tube 17. Thus, the upper end of the iron B will be adjusted so that the seat will be permanently set to the desired height above the floor. When the seat adjustment has been effected the end 15 of the control member 12 is withdrawn from engagement with the bottom of the annular groove 10 to uncouple the housing and the screw post.

The lower end of the housing 4 operates within a tubular shield or pedestal cover 18 carried by the chair base A and also telescopically receives the upper end of the base tube 17 in which the nut 16 is secured against rotation in any appropriate manner, such, for example, as being confined between the shoulder 19 of the base tube and the inwardly turned tongues 20 which fit into appropriate slots in the upper end of the nut.

One of the features of this construction is that it is of the top bearing rotating type. This is made possible by using V formed threads in the nut 16 and the post 6. The V formed threads ofier sufiicient friction to overcome the friction set up by the disc D. This means that the weight of the chair top will bind the threads of the post and nut and allow the iron B to swivel freely on the lubricous disc D.

In connection with the lower end of the screw post 6 it will be observed that the same is provided with a stop washer 21 at its lower end which is of sufficient diameter to engage the bottom face of the fixed nut 16 as shown in Fig. 1 to limit the upward movement of the screw post 6.

The inner face of the tubular housing member 4 is provided with a nylon or equivalent bushing 22 throughout its length as shown. This bushing may be formed as a seamless tube, or a split tube. Alternatively, it may be a sheet of material bent into circular form before its insertion into the housing so that it will conform to the inner contour thereof. The purpose of the bushing 22 is to provide relatively frictionless engagement with the outer surface of the base tube 17b when the housing 4 is rotated relative to the said tu e.

The lower end of the base tube 17 is secured in the bore 2 of the center hub casting and its open end may be closed by plug button or dust stop 23.

Fig. 1 shows the member 11-15 coupling the housing 4 with the screw post 6 when effecting height adjustment of the post. On the other hand, Fig. 2 shows the same member 11-15 withdrawn from coupling relation to the post as, for example, when it is desired to permit free swiveling movement between the post and the housing. It will, of course, be understood that there may be any desired intermediate positions of the screw post and housing relative to the nut 16, in addition to the extreme locations shown in Figs. 1 and 2.

As the chair iron is lowered, the lower end of the housing 4 may fit into the cavity 3 as will be apparent from the description already given.

The foregoing construction has the advantageous features found in the objects of the invention, and provides a practical and efiicient arrangement of parts.

I claim:

1. A swivel chair adjusting means, comprising, in combination, a chair base including a center hub having a bore and an enlarged cavity terminating the upper end of said bore, a base tube fixed in said bore and extending above the center hub, a nut fixed to the upper end of the base tube and a chair seat supporting member having a tubular housing portion telescopically fitting over the base tubing, a threaded post working in the nut, means for connecting the housing and the post against axial separation, and means for releasably coupling the housing and the post.

2. Swivel chair adjusting means, comprising, in combination, a chair iron including an upper seat at taching portion and a downwardly extending tubular housing, a bushing within said housing, a center hub casting having an axial bore opening at its upper end into an enlarged housing receiving cavity, a base tube fitted at its lower end into said bore and having its upper portion telescopically fitting into said bushing, an adjusting nut fixed in the upper end of said base tube, an exteriorly threaded post working in said nut and having a laterally opening annular groove near its upper end, a set screw on the housing and fitting into said groove to interlock the housing and post against axial separation, and a manually actuated adjustable member carried by the housing and having means entering said annular groove for releasably engaging the post selectively to couple the housing and post or to permit the housing to swivel free of the post.

3. Swivel chair adjusting means, comprising, in combination, a chair iron including an upper seat attaching portion and a downwardly extending tubular housing, a nylon bushing within said housing, a center hub casting having axial bore opening at its upper end into an enlarged housing receiving cavity, a base tube fitted into said bore and having its upper portion extending into said bushing, an adjusting nut fixed in the upper end of said base tube, an exteriorly threaded adjusting post working in said nut, a stop washer carried by the lower end of the post for upwardly limiting engagement with the fixed nut, means for rotatably interlocking the upper end of the post with the housing to prevent their axial separation, and

operator control means on the housing disposed radially of the post and axially movable inwardly to couple the post and housing to enable elevating and lowering of the post relative to the base tube to control chair height and movable outwardly to permit the housing to swivel freely relative to the post after chair iron adjustment has been effected.

4. Swivel chair seat adjusting means, comprising, in combination, a chair base having a bore, a base tube fitted in said bore and terminating at its upper end above the base, a nut fixed in the upper end of the base tube, said nut having internally formed V-threads, a tubular housing fitting over the base tube and having a socket in its upper end, a post including externally formed V-threads meshing with V-threads of the nut and a lubricous friction reducing disk between the upper end of the post and the bottom of the socket, and means for mutually coupling and uncoupling the post and housing whereby, the V-threads of the nut and post under a downwardly directed force against the housing will bind to provide greater friction therebetween than the friction between the housing and the post so that the housing will freely swivel relative to the post on the lubricous disk when the post and housing are uncoupled.

References Cited in the file of this patent UNITED STATES PATENTS 401,379 Sammons Apr. 16, 1889 558,427 Sheridan Apr. 14, 1896 1,923,892 Skillman Aug. 22, 1933 FOREIGN PATENTS 4,710 Switzerland Mar. 16, 1892 

